A NEW ballast stabilisation polymer called XiTrack is being used to prolong the life of ballast and reduce maintenance work.
The polymer is used to hold ballast together, cutting the need for frequent tamping.
Balfour Beatty has adapted the polymer for the railway market from a formula developed by polymer specialist Hyperlast, Herriot Watt University and geotechnical expert 2EI.
The system is a 'half-way house' between ordinary ballast and Slabtrack where rails are attached to a longitudonal concrete slab.
'We've taken ballast technology, which is limited, to make it perform much better, ' said Balfour Beatty Rail technical director Neil Andrew.
The XiTrack system can be used to strengthen areas of ballast which are especially prone to wear and tear. These include curves, viaduct approaches and areas where ground conditions are relatively unstable.
The polymer is applied by pouring it onto level ballast to bind it together while leaving a porous structure for drainage.
XiTrack is much cheaper than Slabtrack and can be applied to existing ballast.
Andrew said that polymer binders had been on the market for many years, but other systems suffered from cracking under extreme weather or loading conditions.
XiTrack is designed to work at high and low temperature extremes. It is to be used near Tonbridge in Kent to provide lateral restraint along curved sections of track to prevent it from buckling in hot weather.